The present invention relates generally to clamps used to control the flow of medical fluid through an intravenous (“I.V.”) tube, and more particularly, to a slide clamp that safeguards against the inadvertent movement of the clamp from an occluding position to a non-occluding position on the tube.
Physicians often desire that medical fluids be delivered to a patient with precision. Therefore, instruments such as infusion pumps are used to regulate the delivery of fluids with a high degree of accuracy. Such infusion pumps provide an occlusion of the fluid line at all times. That is, there is never a direct flow path from fluid source to patient at any time, although the point of occlusion provided by the infusion pump varies. An undesirable situation may occur when fluid is free to flow through the I.V. tube without regulation by the infusion pump or other instrument. This condition is known as a free flow hazard. Activities such as priming of the fluid line or removal of the fluid line from the pump raise the possibility of a free flow hazard. In order to avoid such a free flow situation, a manual clamp may be placed along a portion of the I.V. tube to crimp the tube and occlude the fluid passageway when necessary to stop any flow.
Prior art clamps usable for occluding fluid lines took many different forms, including the commonly known roller clamps and slide clamps. An example of a roller clamp is shown in U.S. Pat. No. 3,802,463. Slide clamps are usually less expensive than roller clamps, operate in a different manner, and are useful with automated activation and deactivation mechanisms. Many slide clamps are formed of a plate having a flow regulating slot formed therein through which the fluid line is disposed. The aperture typically has an occluding section and a flow section. An I.V. tube is mounted through the aperture and is slidable in the aperture to the occluding section, at which the tube is occluded, and to the flow section at which position, fluid flow through the tube is not impeded. Even though the occluding section imposes a high degree of friction to hold the tube in the slot in an occluded configuration, the plate remains susceptible to dislodgement from this configuration by an accidental blow or by snagging. If dislodgement were to occur and the tube move from the occluding section and this movement pass undetected by a nurse or other caregiver, then a potentially dangerous free flow hazard may exist.
A solution to accidental dislodgement has been contemplated by the prior art. By making the tube contacting surface of the aperture extend over the entire depth of the slide clamp, a relatively wide surface is left contacting the I.V. tube in an operative position. This provides a significant frictional force to oppose accidental dislodgement of the I.V. tube relative to the slide clamp between the flow section and the occluding section. However, a drawback to this solution is that the increased frictional resistance imparted by this device may make it difficult to move the tube from the occluded section to the flow section and vice versa. Moreover, increased frictional resistance may lead to rupturing of the tube wall after repeated clamping and unclamping by the clamp.
Hence, a need has been recognized by those skilled in the art for an improved slide clamp that will provide a more secure occluding configuration with a fluid line, yet can be more easily moved to a flow position when desired. A need has also been recognized for a simple design that is both less expensive to manufacture yet more effective in operation. The present invention fulfills these needs and others.